Various disposable and inexpensive cooking utensils, such as containers for use in heating and/or cooking food products, such as hams, roasts, turkeys, etc., have become popular because they are relatively inexpensive and eliminate the need for container cleaning after the heating and/or cooking of the food product has occurred. Such containers are normally formed of a light or thin gauge material such as aluminum foil. Foil containers made from aluminum foil have the heat transference qualities associated with the metal aluminum and because of the minimal amount of metal utilized in the structure, are inexpensive and, consequently, can be disposed of after a single use.
The convenience of having an inexpensive disposable container by utilizing thin gauge metal is achieved with the attendant factor that the container has diminished structural strength. One measure of the structural strength of the container is known as the "bend strength." The "bend strength" may be defined as the maximum weight which can be lifted by the container prior to the formation of one or more deflection points in the container. A deflection point refers to the formation of a buckle along one of the sides of the container. Thin gauge foil containers are inherently weak and are incapable of carrying heavy loads without bending. Obviously, if the gauge of the metal is increased to increase the "bend strength" of the container, the container cost will also increase.
To achieve added structural strength without increasing the metal gauge and, at the same time, enhance the aesthetic appeal of the container, it is customary to form ribs of varying sizes and designs in the bottom panel and sides of a container. However, the number, shape, and size of the ribs are limited by the elongation capacity of the type of metal and gauge selected. A gauge that is too thin may result in the tearing of the foil as it is formed while a gauge that is too thick may be too difficult to form around complex shapes and sharp angles. Also, the number and depth of the ribs is limited by the elongation capacity, and a tradeoff between the number, shape, and size of the ribs is usually required.
Also, controlled wrinkles or folds are often incorporated in the sides, and the rim of the container is curled or beaded in a variety of ways to increase the overall structural strength of the container. Heretofore, these strength-enhancing features have been generally successful in producing inexpensive and aesthetically-acceptable disposable foil containers suitable for steaming, heating, and/or cooking food products. However, additional strengthening means are still desirable, especially in the bottom panel of larger containers such as those used for cooking heavy loads such as roasts, hams, and turkeys.